laconicd/x/evm/statedb/access_list.go
yihuang e6c9b7723b
evm: improve test coverage of statedb package (#888)
Closes: #876
- coverage: 99.3% of statements
2022-01-06 18:10:51 +01:00

119 lines
4.0 KiB
Go

// Copyright 2020 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package statedb
import (
"github.com/ethereum/go-ethereum/common"
)
type accessList struct {
addresses map[common.Address]int
slots []map[common.Hash]struct{}
}
// ContainsAddress returns true if the address is in the access list.
func (al *accessList) ContainsAddress(address common.Address) bool {
_, ok := al.addresses[address]
return ok
}
// Contains checks if a slot within an account is present in the access list, returning
// separate flags for the presence of the account and the slot respectively.
func (al *accessList) Contains(address common.Address, slot common.Hash) (addressPresent bool, slotPresent bool) {
idx, ok := al.addresses[address]
if !ok {
// no such address (and hence zero slots)
return false, false
}
if idx == -1 {
// address yes, but no slots
return true, false
}
_, slotPresent = al.slots[idx][slot]
return true, slotPresent
}
// newAccessList creates a new accessList.
func newAccessList() *accessList {
return &accessList{
addresses: make(map[common.Address]int),
}
}
// AddAddress adds an address to the access list, and returns 'true' if the operation
// caused a change (addr was not previously in the list).
func (al *accessList) AddAddress(address common.Address) bool {
if _, present := al.addresses[address]; present {
return false
}
al.addresses[address] = -1
return true
}
// AddSlot adds the specified (addr, slot) combo to the access list.
// Return values are:
// - address added
// - slot added
// For any 'true' value returned, a corresponding journal entry must be made.
func (al *accessList) AddSlot(address common.Address, slot common.Hash) (addrChange bool, slotChange bool) {
idx, addrPresent := al.addresses[address]
if !addrPresent || idx == -1 {
// Address not present, or addr present but no slots there
al.addresses[address] = len(al.slots)
slotmap := map[common.Hash]struct{}{slot: {}}
al.slots = append(al.slots, slotmap)
return !addrPresent, true
}
// There is already an (address,slot) mapping
slotmap := al.slots[idx]
if _, ok := slotmap[slot]; !ok {
slotmap[slot] = struct{}{}
// Journal add slot change
return false, true
}
// No changes required
return false, false
}
// DeleteSlot removes an (address, slot)-tuple from the access list.
// This operation needs to be performed in the same order as the addition happened.
// This method is meant to be used by the journal, which maintains ordering of
// operations.
func (al *accessList) DeleteSlot(address common.Address, slot common.Hash) {
idx, addrOk := al.addresses[address]
if !addrOk {
panic("reverting slot change, address not present in list")
}
slotmap := al.slots[idx]
delete(slotmap, slot)
// If that was the last (first) slot, remove it
// Since additions and rollbacks are always performed in order,
// we can delete the item without worrying about screwing up later indices
if len(slotmap) == 0 {
al.slots = al.slots[:idx]
al.addresses[address] = -1
}
}
// DeleteAddress removes an address from the access list. This operation
// needs to be performed in the same order as the addition happened.
// This method is meant to be used by the journal, which maintains ordering of
// operations.
func (al *accessList) DeleteAddress(address common.Address) {
delete(al.addresses, address)
}